Add baked texture to render (Cycles)
Once you have the texture baked you need to assign it as an emission material to the object.

This is pretty simple:


Go to the node editor  
Disconnect any nodes you have plugged into the surface socket on the material output node (you needn't delete them).  
Add an emission shader and an image texture node.  
Select the baked texture on the image texture node and plug it into the color input of the emission shader and plug the emission shader into the surface output.  Make sure the strength of the emission shader is 1.00.


Note that if the camera is animated, baked glossy sharers will not look right.

For further reference, see Andrew Price's Introduction to Baking in Cycles.